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pool losing water?

We have a negative edge pool so I can't do the bucket test to see the difference between evaporation and leaks.
There is a blue tank in the pump room that holds 3000l of watr, this balances out the water in the main pool so I turned off the water autofill on this blue tank and measure dhow much water it lost over 2 days.
It seems to have lost 10cm.
Tank is 1.3m x 1.6m wide so I figured that was about 0.2m3 over 2 days or 200 litres.
This seems like a lot to evaopration doesn't it? Outside temps are about 17 degrees during the day and sunny.

In the pump room, I saw a whole load of calcium deposits roughly from where the bottom of the pool is and the outside wall of the pool seems to have a wet patch aea about 5cmx5cm.

Re: pool losing water?

But it's a new pool, well concrete laid about 1 year ago and tiled so shouldn't really be leaking at all.
Pool is about 8.20m x 4.1m x 1.8m deep
So, you're saying all those calcium deposits and wet patches on the wall below is normal?

The problem with the bucket test is that the pool doesn't lose any water, the water loss happens in the blue tank in the pump room because that acts as a sort of water/air pressure balancing to top the pool up.
I turn the tap filler off in the blue tank but if that loses 10cm over 2 days then that's not necessarily equivalent to 10cm in the bucket is it? Blue tank is 3000l and only about 1x2x1

Re: pool losing water?

What I meant is that if you're only losing about 3mm per day in the pool it's most likely just evaporation.

I'm not saying the deposits are normal, I'm just not sure they're from a leak. They could be from ground water migration.

Shut off the pool equipment, valve off everything, and then run the bucket test. That should tell you if the pool is leaking.

So, isolate the pool from the blue tank so water cannot go anywhere outside of the pool?
Don't think it's ground water, the pool is raised about 5m off road level and surrounded by concrete. Only one side of pool is near earth and most of that rain water should run off down the side (difficult to explain without a picture).
Is it normal for a new pool to have leaks at all though? 100litres a day sounds like a lot of water for a small pool.

What size is the pool?
Where are you located?
What is the temp there?
What is the humidity there?

8.20m x 4.1m x 1.8m deep
Spain
About 17 degrees celsius during the day, strong sunshine but it's winter time in SPain.
Humidity about 40% I guess, comfortable so you wouldn't really notice if it was humid.

Re: pool losing water?

You're losing about 3mm per day in that size pool. At 40% RH it's very possible to lose that much to evaporation.

Yes, isolate the pool from everything else and then use the bucket test. That should tell you if the shell is leaking. You'll have to wait a bit once you shut it off to make sure it has normalized and isn't draining to the surge tank anymore.